Nanoparticle assembly enters the fast lane

October 11, 2006

UPTON, NY -- The speed of nanoparticle assembly can be accelerated with the assistance of the molecule that carries life's genetic instructions, DNA, a team of researchers at the U.S. Department of Energy's Brookhaven National Laboratory recently found. Nanoparticles, particles with dimensions on the order of billionths of a meter, could potentially be used for more efficient energy generation and data storage, as well as improved methods for diagnosing and treating disease. Learning how to control and tailor the assembly of these miniscule particles into larger functional systems remains a major challenge for scientists. The Brookhaven results, published online on October 11, 2006, by the Journal of the American Chemical Society, are a step in that direction.

"Understanding how to self-assemble these types of nanomaterials has applications in all areas of nanotechnology, from optics to electronics to magnetic materials," said the study's lead author Mathew Maye, a Brookhaven chemist. Maye is part of a team of interdisciplinary scientists from Brookhaven's new Center for Functional Nanomaterials (CFN) and the biology department. The researchers found a way to control the assembly of gold nanoparticles using rigid, double-stranded DNA. Their technique takes advantage of this molecule's natural tendency to pair up components called bases, known by the code letters A, T, G and C.

"In biology, DNA is mainly an informational material, while in nanoscience, DNA is an excellent structural material due to its natural ability to self-assemble according to well-specified programmable rules," said Oleg Gang, the Brookhaven physicist who leads the research team. "Using biological materials such as DNA, we are developing approaches to control the assembly of inorganic nano-objects. However, in order to really turn this attractive approach into nanotechnology, we have to understand the complexity of interaction in such hybrid systems."

The synthetic DNA used in the laboratory is capped onto individual gold nanoparticles and customized to recognize and bind to complementary DNA located on other particles. This process forms clusters, or aggregates, of gold particles.

"It's really by design," Maye said. "We can sit down with a piece of paper, write out a DNA sequence, and control how these nanoparticles will assemble."

One limitation to the assembly process is the use of single-stranded DNA, which can bend backward and attach to the particle's gold surface instead of binding with surrounding nanoparticles. This flexibility, along with the existence of multiple forms of single-stranded DNA, can greatly slow the assembly process. In the Brookhaven study, researchers introduced partially rigid, double-stranded DNA, which forces interacting linker segments of DNA to extend away from the gold surface, allowing for more efficient assembly.

"By using properties of DNA, we can increase assembly kinetics, or speed, by relatively simple means without a lot of synthetic steps," Maye said.

The research team probed the synthesized and assembled nanosystems with multiple imaging techniques, using beams of light and electrons as well as high-intensity x-rays at Brookhaven's National Synchrotron Light Source. The scientists look to further improve the controllability of the system, focusing next on the size of the nanoparticle clusters.
-end-
This research was funded by the Office of Basic Energy Sciences within the U.S. Department of Energy's Office of Science. The CFN at Brookhaven Lab is one of five Nanoscale Science Research Centers being constructed at national laboratories by the DOE's Office of Science to provide the nation with resources unmatched anywhere else in the world for synthesis, processing, fabrication, and analysis at the nanoscale.

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation of State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization. Visit Brookhaven Lab's electronic newsroom for links, news archives, graphics, and more: http://www.bnl.gov/newsroom.

DOE/Brookhaven National Laboratory

Related Nanoparticles Articles from Brightsurf:

An ionic forcefield for nanoparticles
Nanoparticles are promising drug delivery tools but they struggle to get past the immune system's first line of defense: proteins in the blood serum that tag potential invaders.

Phytoplankton disturbed by nanoparticles
Products derived from nanotechnology are efficient and highly sought-after, yet their effects on the environment are still poorly understood.

How to get more cancer-fighting nanoparticles to where they are needed
University of Toronto Engineering researchers have discovered a dose threshold that greatly increases the delivery of cancer-fighting drugs into a tumour.

Nanoparticles: Acidic alert
Researchers of Ludwig-Maximilians-Universitaet (LMU) in Munich have synthesized nanoparticles that can be induced by a change in pH to release a deadly dose of ionized iron within cells.

3D reconstructions of individual nanoparticles
Want to find out how to design and build materials atom by atom?

Directing nanoparticles straight to tumors
Modern anticancer therapies aim to attack tumor cells while sparing healthy tissue.

Sweet nanoparticles trick kidney
Researchers engineer tiny particles with sugar molecules to prevent side effect in cancer therapy.

A megalibrary of nanoparticles
Using straightforward chemistry and a mix-and-match, modular strategy, researchers have developed a simple approach that could produce over 65,000 different types of complex nanoparticles.

Dialing up the heat on nanoparticles
Rapid progress in the field of metallic nanotechnology is sparking a science revolution that is likely to impact all areas of society, according to professor of physics Ventsislav Valev and his team at the University of Bath in the UK.

Illuminating the world of nanoparticles
Scientists at the Okinawa Institute of Science and Technology Graduate University (OIST) have developed a light-based device that can act as a biosensor, detecting biological substances in materials; for example, harmful pathogens in food samples.

Read More: Nanoparticles News and Nanoparticles Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.